What is fiber laser?
A fiber laser or fibre laser is a laser in which the active gain medium is an optical fiber doped with rare-earth elements such as erbium, ytterbium, neodymium, dysprosium, praseodymium, thulium and holmium. They are related to doped fiber amplifiers, which provide light amplification without lasing. Fiber nonlinearities, such as stimulated Raman scattering or four-wave mixing can also provide gain and thus serve as gain media for a fiber laser.
The advantages of fiber lasers over other types include:
Light is already coupled into a flexible fiber: The fact that the light is already in a fiber allows it to be easily delivered to a movable focusing element. This is important for laser cutting, welding, and folding of metals and polymers.
High output power: Fiber lasers can have active regions several kilometers long, and so can provide very high optical gain. They can support kilowatt levels of continuous output power because of the fiber's high surface area to volume ratio, which allows efficient cooling.
High optical quality: The fiber's waveguiding properties reduce or eliminate thermal distortion of the optical path, typically producing a diffraction-limited, high-quality optical beam.
Compact size: Fiber lasers are compact compared to rod or gas lasers of comparable power, because the fiber can be bent and coiled to save space.
Reliability: Fiber lasers exhibit high temperature and vibrational stability, extended lifetime, and maintenance-free turnkey operation.
High peak power and nanosecond pulses enable effective marking and engraving.
The additional power and better beam quality provide cleaner cut edges and faster cutting speeds.
Lower cost of ownership.
Fiber lasers are now being used to make high-performance surface-acoustic wave (SAW) devices. These lasers raise throughput and lower cost of ownership in comparison to older solid-state laser technology.
Applications of fiber lasers include material processing (marking, engraving, cutting), telecommunications, spectroscopy, medicine, and directed energy weapons.